The present disclosure relates generally to Over-the-Air (OTA) wireless charging capabilities in portable electronic devices. Conventional smart phones, radios, and other devices with wireless charging capabilities have their receiver (RX) coils located on or at the back of the device, e.g. embedded in the device or as an attachment in the form of a jacket on the back of the device. This is because the front of the device is utilized to accommodate large screen displays and, optionally, a keypad, buttons, or other mechanisms for user input. Due to the form factor of portable devices, it is not possible to have receiver coils on a front side of the device. Accordingly, receiver coils have been located on or at the back of the device to wirelessly charge with corresponding transmitter (TX) coils. However, if the receiver coils are facing away from the transmitter coil, such as when the front of the device is facing the transmitter coil, then the power transfer efficiency is significantly affected due to a metal chassis in the device blocking some portion of the magnetic coupling between the transmitter and receiver coils, as expected. Furthermore, the thickness of the device introduces additional distance between the transmitter and receiver coils in this orientation, such as when the front of the device is facing the transmitter coil.
Accordingly, there is a need for an apparatus and method for full-orientation OTA charging in portable electronic devices.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.